1. Field of the Invention
This invention relates to an image pickup apparatus, such as a video camera, arranged to be capable of operating in completely different image shooting modes such as moving image shooting and still image shooting.
2. Description of the Related Art
A demand for high-density recording has recently increased in the field of magnetic recording. To meet this demand, video tape recorders (hereinafter referred to as VTRs) have come to be arranged to perform recording at a higher density by lowering the traveling speed of the tape. The lower traveling speed of the tape, however, brings about a problem which is as follows: In a case where an audio signal is recorded with a fixed head, for example, the quality of reproduced sounds degrades as it is impossible to make the relative speed of the tape and the fixed head sufficiently high. In one of methods for solving this problem, the length of recording tracks to be scanned by a rotary head on the tape is extended to be longer than the conventional length and an audio signal which has been time-base compressed is recorded within the extension area of the tracks. More specifically, this method is carried out in the following manner: While it has been practiced to wrap the magnetic tape at least 180 degrees around a rotary cylinder in the case of a rotary 2-head helical scanning type VTR, the tape is wrapped, according to this method, at least (180+xcex8) degrees around the rotary cylinder; and an audio signal which has been pulse-code modulated (PCM) and time-base compressed is recorded within the extra wrapped part corresponding to the additional degree xcex8.
FIG. 1 shows the tape transport system of the VTR of the above-stated kind. FIG. 2 shows recording tracks formed on a magnetic tape by the VTR of FIG. 1. In FIG. 1, a reference numeral 1 denotes a magnetic tape. A numeral 2 denotes a rotary cylinder. Numerals 3 and 4 denote heads mounted on the rotary cylinder 2. In FIG. 2, A numeral 5 denotes a video signal recording area of the recording track formed on the magnetic tape 1. A numeral 6 denotes a PCM audio signal recording area of the recording track. The video signal recording area 5 is arranged to be traced by the heads 3 and 4 within the angle range of 180 degrees around the rotary cylinder 2, and the PCM audio signal recording area 6 is arranged to be traced within the additional angle range of xcex8 around the rotary cylinder 2.
As one application example of the method of recording a digital signal in another area while a video signal is recorded within one area as mentioned above, a method of recording a still image within the digital signal recording area 6 in the form of a digital signal has been proposed. Information on one still image can be completely recorded on the magnetic tape 1 by scanning a plurality of the PCM signal recording areas 6. This method not only enables one and the same image pickup apparatus to use one and the same recording medium for still image shooting as well as for moving image shooting but also makes it possible to obtain a still image of a higher picture quality than a still image obtainable by the conventional VTR by reproducing a video signal from one and the same track by stopping the tape travel.
It has been also proposed to combine a recording apparatus of the above-stated kind with a camera into a camera-integrated type VTR (hereinafter referred to as a video camera) which permits still image shooting as well as moving image shooting.
The video camera of the above-stated kind is provided with various automatic control functions such as an automatic white balance control function and an automatic focus control function for optimum image pickup. To carry out these functions, the video camera is provided also with various moving parts such as an actuator for an optical system, etc.
However, the characteristics of these functions are arranged to be optimum only for moving image shooting in general. It has been, therefore, a shortcoming of the conventional video camera of the above-stated kind that the still image shooting cannot be accomplished in an optimum manner because of such characteristics.
This invention is directed to the solution of the problem of the prior art. It is, therefore, an object of the invention to provide an image pickup apparatus which is capable of recording still images in an optimum state as well as moving images by itself.
It is another object of the invention to provide an image pickup apparatus which is arranged to permit smooth switching from moving image shooting over to still image shooting.
To attain these objects, an image pickup apparatus which is arranged as an embodiment of this invention comprises: image pickup means arranged to convert image pickup light obtained from an object into an electrical signal; instructing means arranged to give an instruction for moving image shooting or for still image shooting; driving-control means for driving-control over moving image shooting and still image shooting with predetermined different control characteristics; and setting means for setting the different control characteristics according to the instruction of the instructing means.
The embodiment is capable of performing under apposite control conditions not only the moving image shooting but also the still image shooting.
With the control characteristics appropriately set, switch-over from the moving image shooting to the still image shooting can be smoothly accomplished.
Further, this invention is not limited to the moving image shooting and the still image shooting but is also applied to any cases where the image pickup is to be performed in any of different modes by a single apparatus.
These and other objects and features of this invention will become apparent from the following detailed description of embodiments thereof taken in connection with the accompanying drawings.